Pressing new bearings into tensioners

[Terrorizer]

I am replacing the bearings in my tensioners and I have heard people talk about using a "press". I may have access to one of these but If I dont could I use something like a vice to clamp them into place? I would use a piece of wood to protect the bearing and the tensioner. Also, how easy is it to damage the bearings? I would hate to accidently screw them up and have to buy new ones. Maybe I can have a shop do it for me for cheap or something? Thanks for any info.

 

[rbruso]

Depending on the bearing clearance and size of the vice, you'll likely have issues trying to produce enough force to get the bearing seated. A vice is designed to clamp enough to prevent movement, not to provide a lot of force. Pushing harder on the handle could result in a bent/broken handle or (in the extreme) snapping the main screw drive.

Any shop with a hydraulic press should be able to do the work. It's quick and easy, though they'll likely charge $20-$40.

 

[Off Road SHO]

A vice IS a press, it just uses an inclined plane (the screw attached to the handle) to move one jaw against the other instead of hydraulics like in most presses.

When pressing bearings in or out, to prevent damage to the bearing you must always put force on the race that has the resistance. In other words, if it's the outer race (race is the grooved part of the bearing, always in two's, an inner and an outer on circular bearings like you are talking about) that is going to hold the bearing in the pulley, you put pressure on that outer race. If the inner race will do the holding, say on a shaft, you would put pressure on the inner race.

Try to avoid putting pressure "through" a bearing, such as on the inner race to seat a bearing that is held in by the outer race. Bearings aren't designed to withstand that kind of axial load.

In the pulley that will get the bearing, try and support the pulley as close to the bearing as possible. The further the support is from the bearing, the easier the pulley will deform.

Have I described it well enough or is it as clear as mud now?

Tom

 

[sperold]

Post 3 is good advice.
Often you can get a socket to match the outer race of the bearing (in your case), so that when you do the squeeze, you are not mauling the race seals or crushing your round or tapered bearings.
The parts (inner diameter of your pulley & the outer diameter of the standard bearing) are made to be an interferrence fit, so it will go together nicely, with a little effort.
You have to press the old bearing out, so that will give you the clues on how to put it back in. Sockets are your friends, and use them in pairs.... the bigger one supports your wheel, the smaller one pushes the outer race of the bearing.

 

[SHOmethewayhome]

i'd be more worried about putting the new one on than taking the old ones out.

got a 20 ton press down here if you need it. but like Tom said, a vice with the right application of force to the outside race should handle it.

 

[Off Road SHO]

****, didn't even notice that you are in AZ. Where you be? I have lots and lots of pullies, and if you haven't bought the bearing already, I can show you how to re-grease your old one. Some drugs may be involved...

Tom

 

[Terrorizer]

i'd be more worried about putting the new one on than taking the old ones out.

got a 20 ton press down here if you need it. but like Tom said, a vice with the right application of force to the outside race should handle it.

Really you have a press? Are you familiar with using it and pressing in these bearings? I would hate to destroy one of those 40 dollar mf'ers. How big is that thing? I picture a press being a gigantic hydrolic machine you'd find in a factory but maybe I am wrong, lol.

 

[Terrorizer]

****, didn't even notice that you are in AZ. Where you be? I have lots and lots of pullies, and if you haven't bought the bearing already, I can show you how to re-grease your old one. Some drugs may be involved...

Tom

Thanks for the offer. I am tempted to do that, but considering how deep I already am in this project and the ammount of money I've already spent I think I'm just going to break down and buy the new bearings so I have the piece of mind. I will let you know if I change my mind though.

 

[Terrorizer]

Are the bearings for each tensioner the same size? They have the same NSK number on them and appear to be the same size but sho source has them listed separately as 4 rib and 6 rib.

 

[Terrorizer]

Do you think putting a piece of wood between the vice and the bearing would be safer than a socket around the outer race? Seems to me like it would distribute the force more evenly. If the socket shifts around or isn't lined up just right I could see it messing up the bearing by pressing on the seal rather than the outer race.

 

[TYSHO]

Are the bearings for each tensioner the same size? They have the same NSK number on them and appear to be the same size but sho source has them listed separately as 4 rib and 6 rib.

Yes, they're the same.

If you want a piece of mind, take it over to Tom's.

 

[Off Road SHO]

Do you think putting a piece of wood between the vice and the bearing would be safer than a socket around the outer race? Seems to me like it would distribute the force more evenly. If the socket shifts around or isn't lined up just right I could see it messing up the bearing by pressing on the seal rather than the outer race.

Again, as long as you press on the part of the bearing that is the "hold". In this case, the outer race. You can use wood as a non scrating buffer if you'd like, but it must push on the outer race.

Tom

 

[SHOmethewayhome]

I'm partial to a correct size socket on the outer race.

i'll get a hold of you tomorrow when i get back to AZ Kyle.

 

[J.L.Gordon]

Harbor freight has a press for 49.99,6 ton bench model.I've used it to press in many tensioner and pulley bearings.

 

[SHOmethewayhome]

Hey Kyle, apparently me and getting to go home and see my wife and kid is going to have to wait another week. I'm stuck back east till at least next wednesday. i suggest PMing offroadSHO begging him to let you come up if he's free tomorrow, and bringing some cash with you to buy a grip of spare parts he has lying around.

 

[Terrorizer]

Today I decided to grow a pair and stop contemplating every little detail that could possibly go wrong with pressing the bearings in. Lo and behold a vice, 2 sockets and 5 minutes got the job done. Thanks you all for your help.

 

[Off Road SHO]

See, now that wasn't so hard was it? It's amazing how many roadblocks we can throw in our own way when we're not familiar with something.

Tom

 

[SHOmethewayhome]

glad to hear